An ignition circuit and a method of operating an igniter (preferably a traveling spark igniter) in an internal combustion engine, including a high pressure engine. A high voltage is applied to electrodes of the igniter, sufficient to cause breakdown to occur between the electrodes, resulting in a high current electrical discharge in the igniter, over a surface of an isolator between the electrodes, and formation of a plasma kernel in a fuel-air mixture adjacent said surface. Following breakdown, a sequence of one or more lower voltage and lower current pulses is applied to said electrodes, with a low “simmer” current being sustained through the plasma between pulses, preventing total plasma recombination and allowing the plasma kernel to move toward a free end of the electrodes with each pulse.

An ignition circuit and a method of operating an igniter (preferably a traveling spark igniter) in an internal combustion engine, including a high pressure engine. A high voltage is applied to electrodes of the igniter, sufficient to cause breakdown to occur between the electrodes, resulting in a high current electrical discharge in the igniter, over a surface of an isolator between the electrodes, and formation of a plasma kernel in a fuel-air mixture adjacent said surface. Following breakdown, a sequence of one or more lower voltage and lower current pulses is applied to said electrodes, with a low “simmer” current being sustained through the plasma between pulses, preventing total plasma recombination and allowing the plasma kernel to move toward a free end of the electrodes with each pulse.

An electronic circuit (101) for controlling a spark of a spark plug (SP1) in a capacitor discharge ignition system (100) for a combustion engine. The electronic circuit (101) comprises an ignition coil (110) dimensioned and configured to provide current to the spark plug (SP1), an ignition capacitor (C1) dimensioned and configured to supply energy to the primary winding (L1), an voltage source (130) dimensioned and configured to supply energy to at least one of the ignition capacitor (C1) and the primary winding (L1), a first switch (SW1) connected to the first primary terminal (TL1) and the first source terminal (TS1), a second switch (SW2) connected to the second capacitor terminal (TC2) and the second source terminal (TS2), and a third switch (SW3) connected to the second capacitor terminal (TC2) and the first source terminal (TS1). A capacitor discharge ignition system (100) including the electronic circuit (101) and a combustion engine including the capacitor discharge ignition system (100).

An ignition circuit and a method of operating an igniter (preferably a traveling spark igniter) in an internal combustion engine, including a high pressure engine. A high voltage is applied to electrodes of the igniter, sufficient to cause breakdown to occur between the electrodes, resulting in a high current electrical discharge in the igniter, over a surface of an isolator between the electrodes, and formation of a plasma kernel in a fuel-air mixture adjacent said surface. Following breakdown, a sequence of one or more lower voltage and lower current pulses is applied to said electrodes, with a low “simmer” current being sustained through the plasma between pulses, preventing total plasma recombination and allowing the plasma kernel to move toward a free end of the electrodes with each pulse.

In at least some implementations, a method of operating an ignition system for a combustion engine includes charging an energy storage device during at least a portion of the time when the engine is operating, permitting the level of energy stored on the charge storage device to decrease over time after the engine ceases to operate, determining the energy level on the energy storage device when the engine is restarted after having ceased operating, and setting at least one engine operational parameter as a function of the determined energy level. In at least some implementations, the at least one engine operational parameter may include one or more of: richness of a fuel and air mixture to be delivered to the engine, ignition timing, desired engine idle speed.

An electronic circuit (101) for controlling a spark of a spark plug (SP1) in a capacitor discharge ignition system (100) for a combustion engine. The electronic circuit (101) comprises an ignition coil (110) dimensioned and configured to provide current to the spark plug (SP1), an ignition capacitor (C1) dimensioned and configured to supply energy to the primary winding (L1), an voltage source (130) dimensioned and configured to supply energy to at least one of the ignition capacitor (C1) and the primary winding (L1), a first switch (SW1) connected to the first primary terminal (TL1) and the first source terminal (TS1), a second switch (SW2) connected to the second capacitor terminal (TC2) and the second source terminal (TS2), and a third switch (SW3) connected to the second capacitor terminal (TC2) and the first source terminal (TS1). A capacitor discharge ignition system (100) including the electronic circuit (101) and a combustion engine including the capacitor discharge ignition system (100).

In at least some implementations, a method of operating an ignition system for a combustion engine includes charging an energy storage device during at least a portion of the time when the engine is operating, permitting the level of energy stored on the charge storage device to decrease over time after the engine ceases to operate, determining the energy level on the energy storage device when the engine is restarted after having ceased operating, and setting at least one engine operational parameter as a function of the determined energy level. In at least some implementations, the at least one engine operational parameter may include one or more of: richness of a fuel and air mixture to be delivered to the engine, ignition timing, desired engine idle speed.

An ignition circuit and a method of operating an igniter (preferably a traveling spark igniter) in an internal combustion engine, including a high pressure engine. A high voltage is applied to electrodes of the igniter, sufficient to cause breakdown to occur between the electrodes, resulting in a high current electrical discharge in the igniter, over a surface of an isolator between the electrodes, and formation of a plasma kernel in a fuel-air mixture adjacent said surface. Following breakdown, a sequence of one or more lower voltage and lower current pulses is applied to said electrodes, with a low simmer current being sustained through the plasma between pulses, preventing total plasma recombination and allowing the plasma kernel to move toward a free end of the electrodes with each pulse.

An ignition circuit and a method of operating an igniter (preferably a traveling spark igniter) in an internal combustion engine, including a high pressure engine. A high voltage is applied to electrodes of the igniter, sufficient to cause breakdown to occur between the electrodes, resulting in a high current electrical discharge in the igniter, over a surface of an isolator between the electrodes, and formation of a plasma kernel in a fuel-air mixture adjacent said surface. Following breakdown, a sequence of one or more lower voltage and lower current pulses is applied to said electrodes, with a low simmer current being sustained through the plasma between pulses, preventing total plasma recombination and allowing the plasma kernel to move toward a free end of the electrodes with each pulse.

An ignition system for a light-duty combustion engine includes a charge winding, a microcontroller and a power supply sub-circuit. The sub-circuit is coupled to both the charge winding and the microcontroller and includes a first power supply switch, a power supply capacitor and a power supply zener. The sub-circuit is arranged to turn off the first power supply switch so that charging of the power supply capacitor stops when the charge on the power supply capacitor exceeds the breakdown voltage on the power supply zener. In at least some implementations, the power supply capacitor may power the microcontroller and the power supply sub-circuit may limit or reduce the amount of electrical energy taken from the induced AC voltage of the charge winding to a level that is still able to sufficiently power the microcontroller yet saves energy for use elsewhere in the system.